Male sexual impotence is a widespread problem. Many different solutions to this problem have been tried. A main solution currently practised and disclosed in for instance U.S. Pat. Nos. 5,437,605 and 4,841,461 is to implant a hydraulic inflatable/contractible silicon prosthesis in the cavities of the corpora cavernosa of the patient's penis. In fluid connection with this prosthesis is a reservoir implanted in the scrotum. By manual pumping action the prosthesis is filled with fluid from the reservoir to effect erect condition or is emptied of fluid, which returns to the reservoir, to effect flaccid condition.
However, there are several more or less severe disadvantages of this main solution. Above all, the penis is more or less damaged by the operation and it is practically impossible to reverse the operation. Another disadvantage is that rather strong forces act against this implanted prosthesis resulting in a significant risk of the prosthesis being broken. A further disadvantage is that hard fibrosis created around the reservoir over time may cause malfunction of pumping components. Thus, the created fibrosis will sooner or later become a hard fibrotic layer which may make it difficult to pump the reservoir. Yet a further disadvantage is that the use of hydraulic fluid always entails a risk of fluid leaking from the prosthesis. Furthermore, it is a rather complicated task to manually pump the reservoir when erection is desired.
Another solution is to inject a substance in the vein system to achieve erection. However, injections are painful and complicated for the patient.
Yet another solution to achieve erection is to restrict the blood flow leaving the penis. For example, U.S. Pat. No. 4,829,990 discloses two hydraulically operated inflatable cuffs wrapped around the respective crura. Again, a disadvantage of such a solution is that it entails a risk of hydraulic fluid leaking from the cuffs.
Another example of the solution to restrict the penile blood flow is found in U.S. Pat. No. 4,828,544, which discloses an artificial fistula system surgically implanted and providing a primary fistula between the femoral artery and the femoral vein and a secondary fistula for leading blood from the primary fistula to the penis. An inflatable balloon engages the primary fistula between the secondary fistula and the vein. The balloon is in fluid connection with a manually compressible reservoir implanted in the scrotum. Besides the risk of fluid leaking from the balloon, a further disadvantage of this latter example is that it requires delicate surgery.
Yet another example of the solution to restrict the penile blood flow is found in EP 1253877 B1, which discloses an adjustable restriction device that directly clamps a portion of the normal penile tissue or the prolongation thereof of the patient. There is an adjustment device that mechanically adjusts the restriction device to temporarily contract the portion of the normal penile tissue or the prolongation thereof to restrict the blood flow leaving the penis, when the patient desires to achieve erection.
A serious disadvantage of the prior art devices that constrict clamp the patient's penile tissue to restrict the exit penile blood flow is that the element that constricts, clamps or restricts the penile portion may injure the tissue wall of the penile portion. Thus, a consequence of the element's constricting action on the penile portion is that the element might erode into the penile portion over time, and in a worst case, penetrate the constricted penile portion of the penile portion.